Opus cycles power every 5 secs....

Hereís the deal, I built a 933 PIII IBM Netvista CarPC. Inside I have a 5.25 DVD, 3.5 160 gig HD, 128 megs of ram, and a Opus 90 watt power supply a DCX3.

The set up in the car is as follows, Main battery 12v, to Aux Battery 12v, 7mah, to Opus. Works great on my desk with the spare battery that I am using for a backup battery in my car connected to the Opus. Obviously after some time the charge goes down and I can no longer boot, thus the voltage dropped below 10.6volts. So I tested the PC for 2 hours in the house, and found it to work perfectly off the Opus power supply.

Now I install it in the car, and try to power it, starts up for 4-5 secs, turns off, for 2-3 secs, turns back on. This happened to me once when I used a DC power supply that only output 2amps, so I thought ok, test to see the amps drawn, and I found it was 4 amps. Thus my problem, Iím using 12 awg wire, like it says to in the Opus install guide. Now the CarPc is in the trunk the battery is under the hood, I thought possibly the wire run is too long, but this seems untrue. So I thought, I have a batcap for my audio system in the trunk too, why not hook the carPC up to that.

Hooked it up, made sure the ground was to the frame, and still no solid power from the Opus. Iím at the end of my rope, I donít know what else to try, tonight Iím picking up a second of the same battery from Radio shack to wire by itself in the trunk direct to the PC, same as I had it hooked up in test runs in the house.

At first you say that you are using the same battery that you were using in the house. If you use this same setup in the car, then this makes no sense, it should work. Then u mention a Shack battery???
Did u use the same 12g wire in the house? Check the wire, or use a different one.(I'd go bigger anyway)
Hook up a volt meter at the Opus, I bet the voltage will drop too low.
I'm not familiar with a Shack battery that would provide enough juice, <confused>
Bottom line is, it worked in the house, so the Opus is good. It doesn't work in the car? I'd say you have a problem getting enough volts to the Opus. Check power or ground.
Let us know what fixed it, hope I helped (some)

Voltage

Voltage is perfect, even with the car not running. I didn't get a battery at RS, i thought they would have one to fit my application, the battery i got was off eBay, and was said that it could be used in a car application. In the house when i had the Battery wired to the Opus, I used 18 awg wire and not more then 1 foot of it to the Opus. I'm not getting the amps i should be, but the wire i am using supports 20 amps in a household set up, so there is no reason why it isn't working. Not to mention i used another battery, that is a battery and capacitor that is not more then 2 feet from the Opus in the car, and still just cycles power on and off.

Voltage is perfect, even with the car not running. I didn't get a battery at RS, i thought they would have one to fit my application, the battery i got was off eBay, and was said that it could be used in a car application. In the house when i had the Battery wired to the Opus, I used 18 awg wire and not more then 1 foot of it to the Opus. I'm not getting the amps i should be, but the wire i am using supports 20 amps in a household set up, so there is no reason why it isn't working. Not to mention i used another battery, that is a battery and capacitor that is not more then 2 feet from the Opus in the car, and still just cycles power on and off.

Any other ideas?

Well besides the fact that the 90W isn't ment for PIIIs, I think you should check your wireing. You probably have a bigger voltage drop in your car compared to your house. I presume you use different wireing in the car...
Look at the LEDs thats what they'r there for. Check with the manual what error codes mean what..

I'll spout simplistic opinions for hours on end.
Ridicule anyone who disagrees with me,
and generally foster divisiveness,
cynicism and lower level of public dialog!

Thanks for the 2cents, getting there...

The 90 watt power supply is more then enough, this PC came with a 70 watt ac power supply stock. So i know it is big enough, plus like i said it worked on my desk hooked into a 12v 7mah battery, worked for almost an hour before dropping below 10.6 volts.

As far as the LED blinking, it blinks once, showing idle, then the system powers on by itself for 5-6 sec, then off again, and one blink on the Opus-90 then powers it self on again for 5-6 sec. When I look at the load it shows 4 amps, which is not enough amps. But the wiring is 12 gauge house hold wiring, which should be more then fine for the car. There is something here we are all missing, but i cannot figure it out....

If anyone has done a carPC, and is NY, I would be willing to travel for a 2nd opinion, my good friend is an RPI electrical engineer, and was baffled.

I don't know if you if you solved this issue or not, and do I realize this is an old thread. Even so, I thought it might be helpful to point something out.

This may not be a problem with your Opus or power source, but rather your Netvista's, the motherboard in particular. They are known to have weak/faulty capacitors that leak or burst ,causing all sorts of problems. Google "IBM Netvista capacitors" and you'll get a better idea of what I'm talking about. Open up the case and see if any of the capcitors on the mobo are buldging or leaking anything.

Here's a link to a guys page describing similar problems with his Netvista.

Lucky me I just bought one off ebay right before discovering about this!